Gear Ratio Calculator

Using the form below, you can obtain a good indication of the relationship between pedal effort, cadence and bicycle speed in different gears. This can help you in finding the most suitable gear ratios for your bike, a very important factor if you are building a fixed gear or single speed vehicle.

Understanding the results

Gear inches express gear ratios in terms of the diameter of an equivalent directly driven wheel. A similar system customarily used by continental European cyclists is metres of development, and measures the theorical distance travelled with each turn of the crank.

Reading the result is simple: higher is the value, harder is the chosen gear combination. An hard combination makes your bike go faster, but more effort is required to keep the same cadence.